This invention relates to a forced air cooled type magnetron device in which the configuration of the cooling fins is improved for enhancing cooling effect and which is suitable for mass-production.
Most of the presently used magnetrons are contained in an air duct disposed substantially perpendicular to the axis of magnetron and having a square cross-section for effecting forced cooling. However, it has been desired to develop improved cooling fins having higher cooling efficiency and being easy to manufacture.
With the conventional flat plate type cooling fin, at the corners of the square air duct no fin is present so that air flowing through these portions does not contribute to the cooling. To solve this problem and for the purpose of dissipating the heat generated during the operation of a magnetron, it has already been proposed to use an improved construction of the cooling fins in which fins near the opposite ends of the magnetron tube are bent at larger angles than those at the intermediate portion so that the spacings between the outer ends of adjacent fins are made to be larger near the opposite ends than the spacings between those at the intermediate portion and in which the outer ends of the cooling fins are present also at the corners of the duct, as disclosed in Japanese Utility Model Application Laid-Open No. 28954/1976. This construction, however, increases the number of types of the cooling fin so that it is not suitable for mass production.